Rail flaw detector mechanism



April 20, 1937. E. G. SPERRY ET AL 2,077,312

RAIL FLAW DETECTOR MECHANISM Filed March 9, 1935 10 29 f7 {20 v 25 28 I32 v 21 2B o o 22 o o 25 3 \Hr 1 11 1 18 1'15- /5 1 F F F] F F F F F F FFl F F g I i 4\U L Ll A 25 1 16 \l L F 25 \L Wm Edward G. Sperrg arcourtC. Drake Mung Patented Apr. 20, 1937 UNITED TAT S RAIL FLAW DETECTORMECHANISM Edward G. Sperry, Brooklyn, and Harcourt C. Drake, Hempstead,N. Y.,' assignors to. Sperry Products, Inc., Brooklyn, N. Y., acorporation of Newyork Application March 9, 1935, Serial No. 10,142

2 Claims.

. This invention relates to rail flaw detector cars adapted to travel onrailroad tracks and detect fissures inside the rails. More particularly,the invention relates to the Sperry rail flaw detector car wherein adetector mechanism is suspended from each side of the car to cooperatewith the respective rail. Such mechanisms include detector means mountedon' a carriage and said carriage is in turn mounted for independentmovement with respect to the car body. It has been found that thedetector carriage, because of its freedom of movement, sometimes droppedinto the spaces between the various parts comprising -a frog, afterpassing a switch, and was unable to ride up on the succeeding rails.v Insome instances, the carriagewas jammed in the spaces between the partsof the frog and was severely damaged.

It is the principal object of this invention, therefore, to providemeans which will prevent the detector carriage from falling into thespaces between the parts of a frog. By this means, possibility of damageto the detector carriage is avoided.

Further objects and advantages of this invention will become apparent inthe following detailed description thereof.

In the accompanying drawing,

Fig. 1 is a side elevation of a portion of a Sperry rail fiaw detectorcar showing my invention applied to the detector carriage thereof. I

Fig. 2 is a plan view, partly diagrammatic,

' showing the location on the rail of the parts of the mechanism asheretofore employed.

Figs. 3 and 4 are views partly sectioned vertically, showing theoperation of this invention on a portion of a frog indicated at ll'inFig. 2.

Fig. iii is a modified form of the invention.

Referring to the drawing, there is disclosed in Fig. I the Sperry railflaw detector mechanism as applied to a Sperry rail flaw detector car. Aportion of the car body III is disclosed, within which is supported agenerator G for supplying current to the rail by means of sets ofbrushes II and I! to establish an electromagnetic field surrounding therail. The flux in said field will be uniform as long as there are no.flaws therein, but when a flaw is present the flux in said field isdistorted. 'Such distortion of the field is detected bymeans of a pairof induction coils l5, spaced in tandem along the rail. Said coils areof equal inductance and oppositely wound. and as the car travels alongthe rail they normally cut a constant and equal number of lines offorce. On entering a region of flaw, one coil will cut a differentnumber of lines of force from the other to generate a differential E. M.F. which after being suitably amplified may be I caused to operate anysuitable indicator, such as a pen on a chart, and any suitable railmarking means, as, for instance, a paint gun. coils are mounted in ahousing l6 carried by a detector carriage ll adapted to ride on the railby means such as wheels l8. Said detector carriage is in turn supportedon a current brush carriage 20 by means of loosely fitting bolts 2| andsprings 22 which constitute a limited universal joint which permits thedetector carriage to move independently of carriage 20, both laterallyand vertically and thus adjust itself to irregularities in the railsurface. The current brush carriage 20 supports the currentbrushes H andi2 and may be supported on the rail by means of wheels 25 and supportedon the car body by means of piston rods 28 connected to pistonsoperating in fluid pressure cylinders 29.

The current brush carriage 20 is normally held in raised position bymeans of retractile springs 3i and cables 32, 33, but when it is desiredto lower the carriage into engagement with the rail, fluid pressure,such as compressed air, is admitted to the cylinders 29 todepress thepistons and thus lower the carriage against the action of the retractilesprings,

In Fig. -1 it will be seen that the detector carriage is mounted on aplurality of supports comprising sets of wheels. Referringto Figs. 2 and3, it will beseen that heretofore each of said supports comprised twonarrow wheels l8 mounted on an axle, said wheels being purposely madenarrow to enable said wheels to follow the contour of the rail surfaceand ride into each ir- I regularity so as to maintain the inductioncoils always at a constant distance above the rail surface regardless ofthe irregularities therein. Referring to Figs. 2 and 3 it will be seenthat as the detector carriage approached a frog it was the openingbetween two parts of the frog at a point such as indicated at 4-4because of the narrowness of the wheels, and it has been found that saidwheels sometimes remained in said space without riding up on the railportion of the switch so that the detector carriage was at timesseverely damaged by reason of being wedged into the said space.

To remedy the above condition. we have shown (see Fig. 4) each wheel asprovided with an extension which, in one form of our invention, may takethe form of a hollow cylinder 40, preferably made Said ' possible forthe forward set of wheels to drop into of aluminum or other light metalso as not to add appreciably to the weight, and of somewhat smallerdiameter than the wheels so as normally not to contact with the rail. Itwill be seen, however, that when the detector carriage approaches. afrog, one or both cylindrical extensions of the leading pair of wheelswill always-ride upon the rail parts of the frog to prevent the wheelsfrom dropping intothe space between the rail parts, thus preventingderailment of the detector carriage and damage thereto, and insuringthat the wheels will ride upon the rail surface after the frog has beenpassed over.

In Fig. 5 we have disclosed a modified form of the invention. In thisform, the extension ll tapers outwardly from the wheel portion l8", thediameter of the extension at the wheel portion being substantially thesame as the wheel portion proper.

In accordance with the provisions of the patent statutes, we have hereindescribed the principle and operation of our invention, together withthe apparatus which we now consider to represent the best embodimentthereof, but we desire to have it understood that the apparatus shown isonly illustrative and that the invention can be carried out by otherequivalent means. Also, while it is designed to use the various featuresand elements in the combination and relations described, some of thesemay be altered and others omitted without interfering with themoregeneral results outlined, and the invention extends to-such use.

Having described our invention. what we claim and desire to secure byLetters Patent is:

1. In a rail flaw detector mechanism, means responsive to flaws, acarriage for said responsive means, a support for said carriageproviding universal movement thereof, said carriage having wheelsadapted to ride upon the rail, each of said wheels comprising a portionadapted normally to engage the rail, said portion being so formed thatit would tend to fall into the space between the rail parts of a frog,and an extension on the outside of each portion, said extension having asurface adapted to engage the parts of the frog, said surface taperingoutwardly throughout its entire length from the respective wheelportion.

2. In a rail flaw detector mechanism, means responsive to flaws, acarriage for said responsive means, a support for said carriageproviding universal movement thereof, said carriage having wheelsadapted to ride upon the rail, each of said wheels comprising a portionadapted normally to engage the rail, said portion being so formed thatit would tend to fall into the space between the rail parts of a frog,and an extension on the outside of each portion, said extension having asurface adapted to engage the parts of the frog, said surface taperingoutwardly throughout its entire length from a diameter substantiallyequal to the diameter of the respective wheel portion.

EDWARD G. SPERRY. HARCOURT C. DRAKE.

